docs: def handle_CR(self, value):
          """
          Parses cited references.
          """
          citation = self.entry_class()
  
          value = strip_tags(value)
  
          # First-author name and publication date.
          ptn = '([\w\s\W]+),\s([0-9]{4}),\s([\w\s]+)'
          ny_match = re.match(ptn, value, flags=re.U)
          nj_match = re.match('([\w\s\W]+),\s([\w\s]+)',
                              value, flags=re.U)
          if ny_match is not None:
              name_raw, date, journal = ny_match.groups()
          elif nj_match is not None:
              name_raw, journal = nj_match.groups()
              date = None
          else:
              return
  
          datematch = re.match('([0-9]{4})', value)
          if datematch:
              date = datematch.group(1)
              name_raw = None
  
          if name_raw:
              name_tokens = [t.replace('.', '') for t in name_raw.split(' ')]
              if len(name_tokens) > 4 or value.startswith('*'):    # Probably not a person.
                  proc = lambda x: _strip_punctuation(x)
                  aulast = ' '.join([proc(n) for n in name_tokens]).upper()
                  auinit = ''
              elif len(name_tokens) > 0:
                  aulast = name_tokens[0].upper()
                  proc = lambda x: _space_sep(_strip_punctuation(x))
                  auinit = ' '.join([proc(n) for n in name_tokens[1:]]).upper()
              else:
                  aulast = name_tokens[0].upper()
                  auinit = ''
  
              setattr(citation, 'authors_init', [(aulast, auinit)])
  
          if date:
              date = int(date)
          setattr(citation, 'date', date)
          setattr(citation, 'journal', journal)
  
          # Volume.
          v_match = re.search('\,\s+V([0-9A-Za-z]+)', value)
          if v_match is not None:
              volume = v_match.group(1)
          else:
              volume = None
          setattr(citation, 'volume', volume)
  
          # Start page.
          p_match = re.search('\,\s+[Pp]([0-9A-Za-z]+)', value)
          if p_match is not None:
              page = p_match.group(1)
          else:
              page = None
          setattr(citation, 'pageStart', page)
  
          # DOI.
          doi_match = re.search('DOI\s(.*)', value)
          if doi_match is not None:
              doi = doi_match.group(1)
          else:
              doi = None
          setattr(citation, 'doi', doi)
          return citation